Mechanical properties and morphology of polypropylene composites. Talc-filled, elastomer-modified polypropylene

✍ Scribed by J. E. Stamhuis

• Publisher: Society for Plastic Engineers
• Year: 1984
• Tongue: English
• Weight: 657 KB
• Volume: 5
• Category: Article
• ISSN: 0272-8397
• DOI: 10.1002/pc.750050308

✦ Synopsis

Abstract

The balance of impact strength and rigidity of polypropylene can be significantly improved by physical blending of the polypropylene with a talc filler and a variety of elastomer types. Unsaturated elastomers were found to be effective impact strength improvers in 70/15/15 percent PP/elastomer/talc composites, whereas saturated elastomers gave rise to a high stiffness of such compounds. This is attributed primarily to different tendencies of the elastomers to coat the filler surface. Studies on a wider range of compositions, using a butadienestyrene‐butadiene (SBS) block copolymer and a ethylene‐propylene‐diene (EPDM) terpolymer as representatives of the two elastomer classes, indicated that at high stiffness levels (flexural modulus > 1.6 GN/m^2^), the composites with SBS show the best balance of properties, whereas at higher impact levels EPDM leads to a higher rigidity and impact strength. On the basis of morphological studies such differences can be explained qualitatively, in spite of the complex structure of these composites.